Ovidiu Savin and Enrico Valdinoci Regularity of nonlocal minimal cones in dimension 2 (19K, LaTeX) ABSTRACT. For any $s\in(0,1)$, we consider sets of minimal $s$-perimeter in $\R^2$. We prove that there are no $s$-minimal cones other than the half-planes and that all the $s$-minimal sets are locally $C^{1,lpha}$.